Con artists make money through deception. They lie, cheat and fool people into thinking they've happened onto a great deal or some easy money, when ­they're the ones who'll be making money. If that doesn't work, they'll take advantage of our weaknesses -- loneliness, insecurity, poor health or simple ignorance. The only thing more important to a con artist than perfecting a con is perfecting a total lack of conscience.

What does the average con artist look like? Despite what you may think, he isn't always a shady-looking character. A con artist is an expert at looking however he needs to look. If the con involves banking or investments, the con artist will wear a snappy suit. If it involves home improvement scams, he'll show up wearing well-worn work clothes. Even the basic assumption that the con is a "he" is incorrect: there are plenty of con women too.

­You might think you can spot a con artist because he's someone you instinctively "don't trust." But the term con artist is short for confidence artist -- they gain your confidence just long enough to get their hands on your money. They can be very charming and persuasive. A good con artist can even make you believe he is really an old friend you haven't seen in years.

Con artists do share certain characteristics, however. Even the best con can only go on for so long before people start getting suspicious. For that reason, con artists tend to move frequently. They may have a job that allows this, or they might claim to have such a job. Railroad worker, carnival worker and traveling salesman are all parts con artists play to cover up their constant relocations.

It would be impo­ssible to catalogue every con, because con artists are inventive. While many cons are simply variations on ones that are hundreds of years old, new technologies and laws give con artists the opportunity to create original scams. Many cons tend to fall into a few general categories, however: street cons, business cons, Internet cons, loan cons and home improvement cons.